The net/sslh port

sslh-2.3.1p1 – SSL/SSH multiplexer (cvsweb github mirror)

Description

sslh accepts HTTPS, SSH, OpenVPN, WireGuard, tinc, XMPP and other
protocols on the same port, demultiplexing them based on probes of
the first packet. This makes it possible to connect to any of these
servers on port 443 (e.g. from inside a corporate firewall, which
almost never blocks port 443) while still serving HTTPS on that
port. TCP and UDP are supported. TLS probing can use SNI and ALPN.

Three binaries are provided: sslh-fork, sslh-select and sslh-ev.
-fork has higher overhead, but processes are isolated and restarts
don't disrupt active connections. -select and -ev avoid multiple
processes: of the two, -ev should be lower overhead but is newer;
-select is more well-tested.

WWW: https://www.rutschle.net/tech/sslh/README.html